Corrosion generally refers to an electrochemical process by which a metal is converted to metal oxides. Corrosion is destructive to metallic articles of manufacture and therefore is undesirable. To prevent or slow down the process of corrosion, an anti-corrosion (corrosion-resistant) coating may be applied to the outer surface of a metal, i.e., the surface exposed to the environment. Generally an anti-corrosion coating is, or includes, a formulation effective for resisting degradation due to moisture, salt, oxidation, or chemical exposure. Anti-corrosive behavior provides additional protection in altering the fundamental mechanisms for corrosion, in addition to slowing them down. The adequate function of such coatings is critical, as premature failure of valuable articles of manufacture due to corrosion can have significant financial consequences as well as pose safety risks in the case of objects providing structural support. Therefore, for many types of metal objects, it is desirable to monitor corrosive activity to facilitate the ability to take remedial action as needed and on a timely basis. Anti-corrosion coatings, however, are not inherently capable of monitoring corrosive activity.
Therefore, it would be desirable to add functionality to anti-corrosion coatings and other types of coatings that enables the monitoring and early detection of corrosion. Such functionality could provide a significant value-added feature that could save time and money for the end user and, depending on the type of metal article involved, promote safety measures such as by enhancing the prevention of catastrophic structural failure.